public string Save(CourseAssign aCourseAssign) { bool check = aCourseAssignGateway.IsCourseAssigned(aCourseAssign.CourseId); if (check != true) { aCourseAssign.RemainingCredit = aCourseAssign.RemainingCredit - aCourseAssign.CourseCredit; int rowAffected = aCourseAssignGateway.Save(aCourseAssign); if (rowAffected > 0) { return("Successfully Saved"); } else { return("Saving failed"); } } return("Course Already Assigned"); }